1. Field of the Invention
The present invention relates to an information processing system that can process metadata-added electronic data. Furthermore, the present invention relates to an information processing system that can add metadata to electronic data.
2. Description of the Related Art
Recent personal computers, digital still cameras, digital video cameras, and hard disk recorders are electronic devices capable of generating electronic data and storing generated electronic data. Thus, an information processing apparatus is required to process a large amount and various kinds of (or a wide variety of) electronic data generated and stored by these electronic devices.
To effectively utilize a large amount and various kinds of electronic data, it is preferable that an information processing system can acquire necessary electronic data anytime and can reuse the acquired electronic data.
Such a system can be realized by a unit configured to execute a method for adding auxiliary electronic data (related data) to electronic data. In general, this kind of auxiliary electronic data can be referred to as “metadata.”
If metadata is added to electronic data beforehand, a user can retrieve and acquire any electronic data to which metadata is added (hereinafter, referred to as “main data”) according to various conditions. A user can also acquire information which cannot be directly read from the main body data (e.g., information relating to generation of main body data) based on metadata added to the acquired main body data.
Adding metadata to electronic data is efficient and effective to reuse main body data. Therefore, it is a recent trend that various types of metadata are added to many electronic data.
Using a table format that can display metadata added to respective electronic data is generally known as an example method for displaying electronic data to enable a user to reuse main body data.
Furthermore, the system discussed in Japanese Patent Application Laid-Open No. 10-187743 uses a three-dimensional display screen including a time axis and a predetermined classification axis capable of expressing a group of electronic data and enables a user to visually recognize electronic data and easily reuse main body data.
However, according to the display method discussed in the above-described Japanese Patent Application Laid-Open No. 10-187743, the same electronic data may be displayed at a plurality of different positions depending on a setting of the classification axis. In this case, this conventional method does not explicitly display a mutual relationship between electronic data. Therefore, a user cannot recognize the relevance between two electronic data (e.g., same electronic data) before the user confirms the contents of respective electronic data. Thus, the above-described conventional display method deteriorates the operability of a user who wants to acquire desired electronic data.
Furthermore, according to the above-described display method, one-dimensional classification information is arrayed on the classification axis, and a user cannot recognize a mutual relationship between classification information.
Furthermore, it takes a long time to acquire electronic data if a setting of the classification axis is inappropriate.
In view of the above-described problems, the present invention is directed to enabling a user to easily acquire electronic data from a group of metadata added electronic data.
In general, a user directly inputs or designates metadata to be added to main body data. For example, if there is image data captured by a digital still camera, a user inputs many metadata (e.g., information of captured object, title, message, and comment) via an input unit (e.g., a keyboard). Therefore, it is desired to improve the system to reduce the work load of a user who adds metadata to main body data.
To solve the above-described problem, the system discussed in Japanese Patent Application Laid-Open No. 2002-55748 registers an icon representing metadata if it is frequently added to main body data, and enables a user to simply add metadata contents by moving the icon to the main body data.
The method discussed in the above-described Japanese Patent Application Laid-Open No. 2002-55748 is effective for a user who repetitively performs addition of typical metadata. However, this conventional method is not efficient for a user who frequently increases or decreases the number of metadata items added to each main body data or changes metadata values.